/*
 *   Copyright 2012, Thomas Kerber
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */
package milk.jpatch.access;

import milk.jpatch.access.AccessPatch.Access;

/**
 * Denotes that access flags got modified.
 * @author Thomas Kerber
 * @version 1.0.0
 */
public class AccessFlagsModif extends AccessFlagsPatch{
    
    private static final long serialVersionUID = -3469540111664787425L;
    
    /**
     * The patch of the access.
     */
    private final AccessPatch access;
    /**
     * The patch of the remaining flags.
     */
    private final RestFlagsPatch rest;
    /**
     * The level (class/field/method) of these flags.
     */
    private final AccessLevel accessLevel;
    
    /**
     * 
     * @param access The access patch.
     * @param rest The patch of the remaining flags.
     * @param a The level of these flags.
     */
    public AccessFlagsModif(AccessPatch access, RestFlagsPatch rest,
            AccessLevel a){
        this.access = access;
        this.rest = rest;
        accessLevel = a;
    }
    
    /**
     * 
     * @return The access rights patch.
     */
    public AccessPatch getAccessPatch(){
        return access;
    }
    
    /**
     * 
     * @return The patch for the remaining flags.
     */
    public RestFlagsPatch getRestFlagsPatch(){
        return rest;
    }
    
    /**
     * 
     * @return The access level.
     */
    public AccessLevel getAccessLevel(){
        return accessLevel;
    }
    
    @Override
    public int patch(int flags){
        flags = rest.patch(flags);
        Access a = AccessPatch.getAccess(flags, accessLevel);
        // Erase previous access flags
        flags ^= a.getFlags();
        a = access.patch(a);
        // Add new access flags
        flags |= a.getFlags();
        return flags;
    }
    
}
